CHINO HILLS -- City officials expect to soon file a criminal complaint against a man who operates an alleged Chinese maternity out of a large house in the city.

City Attorney Mark Hensley said he is in the process of filing the necessary paperwork against Hai Yong Wu, who owns the house at 15250 Woodglen Drive.

City staffers and legal council are working to compile evidence against Wu, Hensley said.

"I don't have an exact date, but it will be shortly," he said.

Wu has been in violation of operating a hotel in a residential house as well as altering the original structure of the house without proper permits, Hensley said.

"It appears that whatever is happening at the home has not stopped and whatever violations are at the home is not fixed," he said.

Code Enforcement officials obtained a court-ordered inspection warrant two weeks ago to review the interior of the house and note potential violations.

"And from there, our next step is if they don't come into compliance, which doesn't appear that they're going to, then we would file a criminal complaint or nuisance complaint," Hensley said.

The complaint will detail the allegations against Wu and, when filed in court, will formally begin the criminal process.

Code Enforcement officials have been watching the house since September after 2,000 gallons of sewage was discharged into the city's storm-drain system and San Bernardino County's Flood Control Channel.

"We looked at it for a period for three to four weeks and it turns out that all our investigation showed that it was a maternity birthing center type place," Chino police Cpt. Bill Lenew said.

"There was no criminal activity at least from what we looked at that we were concerned about. But certainly, there were other issues the city was concerned about."

City officials and residents allege pregnant women on a tourist visa or on vacation stay at the house in their last trimester. The woman, they allege, conceal their pregnancy from United States customs officials. Once born, the baby is a U.S. citizen.

Lenew said that it is not illegal to operate a maternity hotel, but it is a violation when such a business operates out of a residential home.

The investigation by city officials followed complaints by residents that streets in the neighborhood were busier than usual. The vehicles, which included luxury cars and vans, went to and from the house that can only be accessed through a small side street off of a cul-de-sac.

The house, which many call a mansion, is just southwest of Chino Hills Parkway and Peyton Drive.